About BLI backup methods
You can choose from the following backup methods when configuring BLI notify scripts:
Table: BLI backup terminology
Term | Definition |
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cold database backup
| A cold database backup is taken while the database is offline or closed. BLI backup shuts down the database and performs either full or block-level incremental backups. This backup method is also referred to in Oracle documentation as a "consistent whole database backup" or a "closed backup." The data from a cold backup is consistent, resulting in easier recovery procedures. To select this backup method, set METHOD to SHUTDOWN_BKUP_RESTART. In an offline backup, all database files are consistent to the same point in time (for example, when the database was last shutdown using typical methods). The database must stay shut down while the backup runs.
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hot database backup
| A hot database backup allows the database to be online and open while the backup is performed. With the Storage Checkpoint facility, this backup method runs database backups in parallel so a database does not need to be in backup mode for a long time. To select this backup method, set METHOD to ALTER_TABLESPACE.
Hot backups are required if the database must be up and running 24 hours a day, 7 days a week. To use hot backups, the database must be in ARCHIVELOG mode. BLI backup uses the alter tablespace begin backup command and the alter tablespace end backup command to put the database into and take it out of backup mode. Oracle documentation refers to this method as an inconsistent whole database backup or open backup. Unlike the cold database backup method, the data in hot backups is fuzzy or inconsistent until the appropriate redo log files (online and archived) are applied after the restore operation to make the data consistent.
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Nodata storage checkpoint hot | A Nodata storage checkpoint hot backup puts the tablespaces in backup mode for the duration of the backup. It uses a Nodata Storage Checkpoint to reduce the amount of file system space consumed. To select this backup method, set METHOD to NODATA_CKPT_HOT. Use this method if all of the following conditions are present: You are backing up multiple Oracle database instances. More than one instance shares the file system. The backup of the instances can overlap in time.
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quick freeze database backup
| The quick freeze database backup is different than an online database backup, because it requires the database to be brought down briefly to take a snapshot or Fulldata Storage Checkpoint of the database image. The Fulldata Storage Checkpoint is created in a few seconds and the database can be restarted immediately. A backup image from a quick freeze database backup is equivalent to a backup image from a cold database backup. You can choose this backup method when you configure BLI notify scripts. To select this backup method, set METHOD to SHUTDOWN_CKPT_RESTART.
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If the database is in ARCHIVELOG mode, you can use all four methods to back up the database. If the database is in NOARCHIVELOG mode, you can only select the cold backup or quick freeze backup.
When you use the cold and quick freeze database backups, the default shutdown command that you use in the bpstart_notify.oracle_bli script is shutdown or shutdown normal. These commands wait for all users to log off before it initiates the shutdown. In some circumstances, even after all interactive users are logged off, processes such as the Oracle Intelligent Agent (Oracle dbsnmp account) can still be connected to the database, preventing the database shutdown. Attempt to use the default shutdown commands to shut down the database cleanly. Alternatively, you can use shutdown immediate to initiate the database shutdown immediately.
